Planet holds 3 Earth’s worth of diamonds

A rocky planet twice the size of Earth appears to be made largely out of diamond, new research suggests.

Yale scientists say 55 Cancri e is an extremely hot planet with a surface of mostly graphite surrounding a thick layer of diamond, below which is a layer of silicon-based minerals and a molten iron core at the center. They estimate that at least a third of the planet’s mass—the equivalent of about three Earth masses—could be diamond.

“This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth,” says lead researcher Nikku Madhusudhan. “The surface of this planet is likely covered in graphite and diamond rather than water and granite.”